Sonoff Motion Sensors False Motion Detection

I've been using these for around 3 months now, maybe more.
I have noticed that for the past week-ish some of my lights have been turning on in the middle of the night. This has only just started.
Investigating the logs and events it is because my Sonoff Motion Detectors, SNZB-03, are detecting motion. The house is in complete darkness and we do not have any pets and my wife would have said if we have ghosts.
It is happening on all of the Sonoff devices. Once a night at random times. It's not one doing it, a light coming on which a different one 'sees' and turns on another light. It's totally random and they are far apart time wise.
I also have some Xiaomi/Aqara devices in these rooms and they are not going active.
I'm using the 'Zigbee - Sonoff Motion Sensor' by Markus.

Anyone else getting false positives with these devices or any suggestions what might be causing it.
It is strange that it has only just started though.
(I've written a rule to notify me when they go active when we are all in bed to track them).

Just a random thought, but are these devices where they might see the airflow from a heating vent? I keep my house lower at night so when the fan first kicks on there is a quick burst of cool air expelled followed by the heated air....

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I have as well but during the day. I am thinking that it might be snow falling that's somehow creating tiny light changes that the inside motion detector picks up? I was thinking about relocating the sensor to be less sensitive to outside movement. I wish I could adjust the sensitivity.

Curious to see what others experience. This only started recently for me (but then again so did first snow of the season).

Thanks for the info but mine are in 4 different rooms. Heating goes off at night and I'm in the UK so cooling really isn't necessary. :slight_smile: so I'm pretty sure it's not. Good call though.

We've had very little snow here and the one pointing to my front door (4m away), which has a small glass panel, could be caused by the outside light coming on (it does with outside motion). No reason for the others though.

The strange thing is that it has only just started. Everything has been hunky dory for months. :thinking:

Just a bit more information.
2 sensors are in one room.
First one triggered motion and turned the light on. Second one stayed inactive.
90 minutes later (roughly) the second one detected motion and turned the lights on and the first one stayed inactive.
This sort of rules out light pollution causing it. For me anyway.

Excluding the units that I have that are affected by pet traffic, I have 2 that are positioned to avoid false triggers (closet and narrow hallway). Those did not report anything unusual overnight, and I do not recall any unexpected behavior from them.

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Yesterday I wrote a rule to notify if motion detected on any of the Sonoff motion sensors during the night.
Guess what. Not a thing. Ggrrrr.
This issue has coincided with the latest set of updates.
Stupid question time.
Could it be possible that a motion sensor detects motion while an update is taking place and somehow it gets auctioned hours later? Personally I cannot see how but who knows. :thinking:

You could make some AL foil covers for the motion sensors so they cannot detect IR movements.
If they still turn the lights on you’ll know it’s not being triggered by motion

Well it's all gone quiet. No more false detection.
The ghost either didn't like us or me walking around in the middle of the night naked frightened him off. :wink:


I've had this happen a couple of times recently too. I've not had the Sonoffs long (maybe 4 weeks ish) and had no problems for the first 3 weeks, but the same sensor has gone active with no one anywhere near twice in a few days. On both occasions, there were only 2 of us in the house, both sat on a sofa in another room. We have no pets. This one is in the exact spot that I previously had a Hue Sensor and I've never had any issues with that, It's not an area effected by air movement and there are no heat sources anywhere in its field of "vision". Odd, It's a shame because otherwise they seem good units and I've got some more on the way. The first false trigger was the day after I'd ordered the others!

Could it maybe be battery levels or bad battery. This happens to my Smarthings motion sensors. As soon as their battery levels get low they start triggering motion lighting for no reason.

My guilty one is showing 100% battery. I don't know how accurate they are on battery levels though. Initially, I'm going to swap its location with another Sonoff to see if its a location issue or a sensor issue.

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Mine will behave for days and then, boom, off they go again giving false notifications.
I did an experiment with a spare one I have.
Put it next to one that gives the odd false motion detection. One did, one didn't.
Both are relatively new so battery life should be good.
As a matter of interest, does your one misbehave shortly after a hub reboot @Geoff_T?

Funny you should ask that, yes. I rebooted yesterday and have had 2 false events since then. Prior to that though I hadn't rebooted for while but still had one false event.

Edit. I am using the inbuilt driver.

I'm using one by markus so I don't think it's a driver issue.
I thought mine were misbehaving after a reboot but wasn't sure if it was me just thinking it was after a reboot.
I think I will stop my bi-weekly reboots and see what happens. I've left it running bi-weekly as a matter of habit.
Interesting to see if anyone else is getting this after a reboot.

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Just an update.
Last night I went into my kitchen and the cabinet lights did not turn on with motion.
3 different sonoff motion sensors should have triggered the lights.
About 2 minutes later the lights came on. Wandered into other rooms and the same thing happened. As it was late I didn't check the logs. I should have done.
Through the night lights turned on and off and it was because the sensors were detecting motion where there wasn't any but it was in the rooms that I wandered in earlier.
This has got me thinking, always a bad thing, as to what could have happened.

Would it be at all possible that the motion detection is 'stuck' in the system somewhere and matures later. Cannot see how but........................ I cannot think of what else could have happened.

For information I have 5 repeaters throughout the house and looking at the zigbee routing table only one Sonoff sensor is using a repeater, 3 are showing in the child data table and 3 in the neighbour table. 5 others are not showing up in any entry.

Any thoughts anyone? :man_shrugging:

EDIT: Also this has only started happening since the latest firmware update but according to the release notes there were no zigbee radio/firmware updates that I can see.

Were all the delays in the other rooms with Sonoff sensors too? It sounds more like a general system issue rather than an individual sensor problem. For 3 different Sonoffs to fail to trigger seems unlikely. But who knows :man_shrugging:

Not much help to solve your problems but I've switched the location of my 2 Sonoffs in an attempt to work out if it was a location or sensor problem, and they've behaved perfectly so far now I'm watching them closely. Typical.

Yes. All Sonoffs.

Can't help but agree with you on this.

I agree.

I've changed a couple to use the HE 'Generic Zigbee Motion Sensor (no temp)' to see if this changes things.
Is this the driver you are using?

Yes that's the one.

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My wife reported the same one night. She said a couple times the lights in our living room came on (I was sound asleep). She turned it off once and then didnt bother the second time. They would not turn off on their own (I have set it to 5 mins). I have a second one in the powder room, that has not turned on the lights on its own, but it doesnt weird stuff. When motion is detected and lights are supposed to turn on at 100%, they turn on at 40% brightness. Using the inbuilt motion app. Using the Sonoff Motion Sensor driver.